Which of the following terms indicates an act of making things spread?

The term that indicates an act of making things spread is "propagation." In various contexts, especially in science and environmental studies, propagation specifically refers to the process of spreading or multiplying something, such as plants propagating through seeds or cuttings, or the propagation of waves in physics. This definition encompasses the essence of spreading, as it involves not just increase in number but also the act of disseminating.

In contrast, the other terms do not convey this sense of spread as directly. "Preclude" refers to preventing something from happening or making it impossible, which is a contrasting concept. "Proliferate," while related to increase, often has a more connotation of rapid multiplication rather than a general act of spreading. "Puckering" involves folding or wrinkling, which pertains to a physical change in shape rather than a dissemination process.

Thus, propagation is the most appropriate term when discussing the act of making things spread in a meaningful and encompassing way.